Back washing apparatus



FIG. 1 is a perspective view of a back washing apparatus showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side elevational thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of a wall in FIG. 1 illustrates environmental structure that forms no part of the claimed design. The surface treatment, which is partially shown for ease of illustration on the cleaning means, represents a conventional material and is understood to continue throughout the surfaces indicated. 

The ornamental design for a back washing apparatus, as shown and described. 